Makes Escalator show scrollbars on some OSX settings (#16852)
Makes Escalator show scrollbars on some OSX settings (#16852)

If the OSX is configured to show scrollbars only while scrolling, Escalator
would previously have its scrollbars hidden underneath the DOM structure.

Change-Id: I6c1a05ba23f6555d9f7f4c484c066c5f7ae63ac3

bmitc/vaadin,carrchang/vaadin,carrchang/vaadin,mittop/vaadin,carrchang/vaadin,carrchang/vaadin,bmitc/vaadin,bmitc/vaadin,mittop/vaadin,mittop/vaadin,mittop/vaadin,bmitc/vaadin